Bottle stopper



W H EU BL BOTTLE STOPPER Sept. 26, 1967 Filed Nov. 5, 1964 INVENTOR. \m PM He bi imam-m. Ross 81' Hakim;

United States Patent M 5 Claims. Cl. 215-41 The invention relates to a bottle stopper made of a synthetic resin for use as a substitute for bottle caps. The bottle stopper comprises a hollow stopper part which is pressed into the mouth of the bottle, a diaphragmlike wall extending across the stopper part, and a jacket part enclosing the neck of the bottle in the manner of a snap fastener.

In practice, bottle caps are generally used for sealing glass bottles for the bottling of beverages having a bead near the mouth of the bottle. These bottle caps consist of cap-shaped blanks containing a sealing agent, such as a small cork disc, which is placed loosely on the filled bottles, and are then flanged or crimped around the head of the bottle neck by special tools.

Although the closures thus produced have a high resistance to pressure, and are extremely tight, the disadvantages for which allowance has to be made have repeatedly been an inducement to replacing the bottle cap by a stopper made of a synthetic resin. The liquid contained in the bottle has frequently a corrosive effect on the metal, so that signs of corrosion appear on the closure after a certain period of storage; such closures have to be avoided for reasons of hygiene. The detrimental fact that many bottles break when the bottle caps are sealed by means of mechanical tools is, however, of particular importance. A high quota of bottle rejects has thus to be expected when such bottle caps are used. Increased financial losses are incurred owing to the fact that the liquid decanted into broken bottles is also lost.

If it were a simple matter to use bottle stoppers made of a synthetic resin as substitutes for bottle caps, the use of metallic bottle caps would certainly have discontinued. In bottle stoppers made of synthetic resin, a cap-shaped stopper part is provided which is pressed into the mouth of the bottle, and a tubular jacket part fitted to enclose the bead around the bottle mouth externally in the manner of a snap fastener, the two parts being interconnected by an end wall. The stopper part performs the main sealing function in the mouth of the bottle, whilst the jacket part not only functions to retain the stopper in the manner of a snap fastener on the bead of the bottle mouth, but also has to perform an additional scaling function.

In one of the known stoppers made of synthetic resin, the stopper part has a diaphragm-like wall to which the vapor pressure of the liquid contained in the bottle is applied, and which transmits that pressure to the stopper wall in order to ensure close contact with the Wall of the bottle.

In one alternative stopper, the stopper part contains a similar diaphragm-like wall, arched upwardly. This stopper has, however, to be heated before its introduction into the mouth of the bottle.

The reason why such bottle stoppers have been unsuccessful in practice is that the tolerances of the bottles at those parts of the bottle mouth at which sealing occurs are so great that the proposed stoppers made of a synthetic resin are capable of sealing only some bottles with adequate; efiiciency, whilst a considerable number of bottles cannot be adequately sealed. It is for this reason that the use of these basically disadvantageous bottle caps continues as before.

3,3437% Patented Sept. 26, 1967 In accordance with the invention, the problem of replacing the bottle caps by bottle stoppers made of a synthetic resin which are at least equal to metallic bottle caps as far as their resistance to pressure and imperviousness to gas are concerned, but by which all tolerances of the bottles are overcome at the same time, is solved, with the result that the proportion of broken bottles obtained during the bottling operation is reduced to the minimum. Surprisingly, it has been found that an advantageous solution to the problem results if the Wall of the stopper part is made of varying thickness along its length, in such manner that, starting from the area in the middle of the wall, which is disposed substantially at the same level as the bead provided on the inside of the jacket part, the thickness decreases in the upward and downward directions, and the beginning of the diaphragm-like wall is disposed externally of the thickest part of the wall at a distance sufficient to ensure that, at the position of its maximum thickness, the stopper Wall can spring back elastically inwards.

Stoppers so constructed sit absolutely tightly and securely in the mouth of the bottle. After the first withdrawal by hand, they can be reinserted tightly as often as desired without deterioration of the fit or of the sealing effect.

In one construction according to the invention, the difference in thickness in the stopper wall should ad vantageously amount to at least 1 mm., and preferably to about 1.6 mm. In accordance with the invention, the outside surface of the stopper wall may be so constructed as to be tapered in the upward and downward directions in the manner of a truncated cone, or may be of a convexly curved section along its longitudinal section.

The bottle stopper according to the invention ensures that the bottle to be sealed is sealed at three annular zones without the sealing effect being impaired by differences in the dimensions of the bottles. The stopper part of the bottle stopper according to the invention is of a thick- Walled, chamfered construction so as to ensure a secure fit and an adequate sealing effect in all bottles of different diameters. An additional sealing effect is obtained at the exposed face of the bead of the bottle contacted by the end wall of the bottle stopper according to the invention, and, thirdly, a further sealing effect and secure anchorage of the bottle stopper below the bead of the bottle are obtained by the beading provided on the jacket of the stopper.

It is of particular importance that the spatial shape of the bottle stopper according to the invention permits the application of an efficient injection-molding technique in which the bottle stopper may be readily removed from the mould. It has to be taken into consideration, that in the interior of the bottle stopper, the cross-section of the area between the stopper part and the jacket part exceeds that of the area near the beading provided on the jacket pa-rt. Upon removal from the mold, therefore, the synthetic-resin stopper will necessarily be deformed at several positions, it being a condition that the deformation should be an elastic deformation in every respect It has been found that the resilience of the end wall of the stopper according to the invention also facilitates the removal of the bottle stopper from the mold and is, moreover, effective to prevent plastic deformation of the stopper parts upon removal from the mold.

In accordance with the invention, furthermore, the inside diameter of the stopper part below the diaphragmlike wall advantageously exceeds that above the diaphragm-like wall. Thus the stopper parts disposed above and below the diaphragm-like wall may be elastically deformed for adjustment to bottles of various tolerances. Further advantageous precautions taken in accordance with the invention consist in the thickest part of the stopa per wall being disposed at substantially the same level as the beading provided on the inside of the jacket part. Moreover, the diaphragm-like wall in the stopper part advantageously juts out axially convexly in the direction of the bottle (i.e. into the latter), and the diaphragm-like wall is braced relatively to the stopper part by radially extending stays.

If, in accordance with a further feature oi the invention, at least one corrugation-like circular groove is provided in the area of the end Wall of the stopper disposed between the jacket part and the stopper part, then the jacket part of the stopper will always be capable of efficient elastic deformation for adjustment to the tolerances.

Finally, in accordance with the invention, the bottle stopper is made of an elastic, and nevertheless hard, synthetic resin (preferably low-pressure polyethylene or polypropylene) which may be injection-molded. It is only this hard material by which an adequately tight and secure fit of the stopper in the mouth of the bottle is ensured, this being not the case with soft polyethylene.

The invention is diagrammatically illustrated by way of example in the accompanying drawing in which:

FIGURE 1 is a longitudinal section through a bottle neck;

FIGURE 2 is a longitudinal section through a bottle stopper of one construction in accordance with the invention;

FIGURE 3 is a longitudinal section through a modification of the stopper illustrated in FIGURE 2; and

FIGURES 4 and 5 are longitudinal sections through stoppers made of a synthetic resin.

FIGURE 1 shows a glass bottle 4 of the kind generally used for cola-beverages, lemonade, fruit juice, beer or the like. Similar bottles are also used for bottle fermentation in the manufacture of champagne. The dimensions of such bottles are standardized in accordance with the purposes for which they are used, the DIN (German Industrial Standards) specification permitting, however, of wide tolerances. Thus, for example, with the internal diameter al a tolerance of 10.5 mm. is permissible. In accordance with the DIN specification, therefore, the inside diameters of the bottles may vary to the extent of one millimeter. In practice, however, one may frequently come across bottles in which these differences amount to as much as 3 mm. This applies similarly to the external diameter d of the head 11 of the bottle 4. The height a of the bead 11, the total tolerance of which should not exceed 0.3 mm., is also of particular importance, this tolerance being, however, exceeded in practice to a substantial extent.

The invention is based on the problem of providing a bottle stopper made of a synthetic resin which is capable of bridging these considerable dilierences in tolerance without having a detrimental elfect on the sealing and secure retaining of the bottle stopper. In providing a solution to this problem, allowance has to be made for the fact that the liquid decanted into the bottles has a considerable internal pressure due to the presence of carbon dioxide or other charging or propellant gas, and it is for this reason that the bottle stoppers should have a resistance to pressures in excess of 5 atmospheres.

One construction of a useful bottle stopper of this kind is shown by way of example in FIGURE 2, in which the bottle stopper 1 comprises essentially a stopper part 2 and a jacket part 3. The stopper part 2 is provided with a jacket wall 5 and a diaphragm-like wall 6, the two walls imparting to the stopper 2 a cross-section shaped like an H-section. The upper hollow space 13 and the lower hollow space 14 characteristic of the construction of the stopper part 2 are thus obtained at the same time.

In the jacket part 3 of the bottle stopper 1 according to the invention, the Wall 7 of the jacket has at its lower end an inwardly projecting head 9 which snaps into the groove 14] provided in the bottle 4 (FIGURE 1). The jacket part 3 is connected to the stopper part 2 by the end wall 8- to the exposed surface of which an embossing,

i an imprint, or like identification of the stopper may be applied.

The relatively thin top wall 8 forms a hinged connection with the heavier upper part 12 of the stopper jacket 2. The outer surfaces 15 and 16 of the jacket are tapered in opposite directions. They meet in the middle zone or area 17 where the stopper portion 2 thus has its maximum girth as well as wall thickness. With a View to the dimensioning of the individual parts, it may be advisable and in many cases even be advantageous for the thickest area 17 in the middle of the stopper part 2 to be at substantially the same level as the head 9 of the jacket part. It is of particular importance that the transition of the diaphragm-like wall or partition 6 to the jacket wall 5 of the stopper part 2 should be disposed at a higher level than the middle zone or area 17 and the bead 9, whereas the middle of the downwardly convex partition 6 facing the bottle 4 may be disposed at the same level as, or at a lower level than, the surface 17 and bead 9.

These are not more or less arbitrary instructions. This design is particularly suitable for equalizing the substantial differences in tolerance of the bottles. Thus, the diaphragm-like wall 6 forms a spring resulting, on the one hand, in a counteracting of the forceful contraction of the jacket wall 5 of the stopper part 2 by a considerable outward force. On the other hand, the diaphragm-like wall 6 permits of a resilient constriction of the lower stopper part 14, for example, upon its introduction into the mouth of a bottle. Finally, the upper part 15 of the stopper 1 is stabilized by the diaphragm-like wall 6 when the wall 7 is pressed vigorously downwards, so that the bead 9 may snap into the groove 10 of the bottle. However, when the neck of the bottle is defective and the bottle should thus really be thrown away, the force of reaction applied by the diaphragm-like wall 6 upon in tr-odu'ction of the stopper is sufficient to cause the bottle to break, which is highly desirable.

The thickness of the jacket wall 5 is such that a secure fit in all bottles of various diameters is ensured by the stopper part 2. The difference in the thickness in the stopper wall 5 should generally amount to at least 1 mm. and preferably to about 1.6 mm. A tight and secure fit of the stopper in all bottles with diiterent degrees of tolerance is ensured by these measurements.

The same diaphragm-like wall 6 also facilitates the removal of the bottle stopper 1 from the mold of the tool. It will be readily understood that, upon removal from the mold, the jacket wall '7 and/or the jacket wall 5 of the stopper part 2 are forced apart by the tool part occupying the space between the walls 7 and 12. The elasticity of the individual walls should, however, be so substantial that, after removal from the mold, the original basic shape of the bottle stopper 1 is restored.

The diaphragm-like wall 6 of the stopper part 2 is the reason why the fit of the stopper part 2 in the mouth of the bottle does not slacken when the jacket part 3 snaps into the groove 10 of the bottle 4. This is due to the fact that when the height a of the bead 11 of the bottle (FIGURE 1) has a positive tolerance, the whole jacket part 3 is expanded and stretched downwards when the bottle stopper is placed on the bottle, with the result that the top part 12 of the stopper wall 5 spreads in the outward direction. This stretching motion would result in a slackening of the stopper part 2 in the mouth of the bottle, this being, however, prevented by the diaphragmlike wall 6 which provides the section 12 of the wall 5 with sufficient space for movement to enable the tolerance in the area of the bottle neck 4 to be bridged without the sealing effect of the stopper part being reduced. This effect would not be obtained if the diaphragm-like wall 6 of the stopper part 2 were disposed at the same level as the end wall 8 of the jacket part 3.

In the construction illustrated by way of example in FIGURE 2, the jacket part 5 of the stopper part 2 is not deformed relatively to the bottle 4. It will be understood that, in the area 17, the stopper part 2 has a closer fit in the mouth of the bottle than is shown in the drawing. FIGURE 2 shows, moreover, that the jacket part 3 spreads in places only to form a collar 18. The collar 18 may have the shape of a lip-shaped flaring. It is used for the application of the closing device generally used for bottle caps, in order to withdraw the bottle stopper 1 according to the invention from the bottle 4.

The bottle stoppers illustrated in FIGURES 3 to 5 hereinafter described are merely different in construction and detail. They perform the function of the stopper illustrated in FIGURE 2 with equal efliciency, but have particular additional properties.

Thus, for example, in the case of the stopper shown in FIGURE 3, the stopper part 2 is modified in that the longitudinal section of its outer surface 19 is of an outwardly curved convex construction. This construction requires the tool to apply more effort, but in some cases a securer fit of the jacket surface 19 in the mouth of the bottle may be obtained.

In the construction according to the invention illustrated by way of example in FIGURE 4, the end Wall 8 of the stopper has a corrugation-like groove having the appearance of a crack, its object being to force the jacket part 3 of the stopper down further than would be possible without the corrugation 20. This, in effect, shifts the hinged connection between the stopper portion 2 and the top wall of the outer annular wall portion 3 radially outwardly toward the outer periphery of the latter portion. Considerable excess tolerances regarding to the distance [1 shown in FIGURE 1 may be accommodated in this manner.

Finally, FIGURE 5 shows a reinforcement of the diaphragm-like wall 6, for example by ribs 21 or the like. It is thus ensured that, when the stopper is pressed into defective bottles, such bottles will break, the stiffness of the stopper being, however, insufficient to break sound bottles.

In all cases a synthetic resin capable of being injectionmolded, but of the greatest possible hardness, for example the synthetic resin sold under the trade name Hostalen, is advantageously used. These substances give the necessary strength without losing elasticity. Thus, for example, upon being forced into excessively narrow bottles, the wall of the stopper part does not remain in the compressed position as would, for example, be the case with soft polyethylene. If the synthetic resin used in accordance with the invention is hard and nevertheless elastic, the construction shown in FIGURE 4 will permit of an adequate initial tension, so that an efiicient sealing and retaining effect can be obtained. The rib-like reinforcement 21 shown in FIGURE 5 may, however, also be provided on the underside of the stopper part 2, and in such a case the wall 5 of the stopper part 2 will be as thin as possible, for example, along the dotted line 22. This thin wall would, of itself, not have suflicient power of resistance to be able to contact the wall of the bottle always closely in all bottles with mouths of different sizes. For this reason, the wall 5 is braced by means of additional stays without the risk of deformation. Whether the inside surface of the wall 5 is a replica of the outer surface is of no decisive importance.

The stopper according to the invention is tasteless and has no harmful effect on the contents of the bottle. The risk of corrosion existing in the case of bottle tops is avoided, so that the bottles can be stored in damp rooms. There is no risk of injury by sharp edges, and no risk of breakage when the stopper is placed on sound bottles. The stopper according to the invention is particularly distinguished by its high resistance to pressure (at least 8 atmospheres) and imperviousness, irrespective of the difference in dimensions of the bottles.

In accordance with the invention, it is particularly advantageous for the bottle stoppers to be heated slightly or moderately before being placed on the bottles by machines to function as substitutes for bottle tops. The heating may, for example, be effected internally of the closing device by heating the feed duct, by irradiation with hot air, or by passing the stoppers through hot water or some other heating medium.

I claim:

1. A bottle closure comprising a stopper unitarily formed of a synthetic resin and consisting essentially of an outer annular wall portion provided with an inner bead and adapted to be forced over the mouth of a bottle whereby said bead underlies a bead of the bottle, a central tubular generally cylindrical stopper portion hingedly connected with said wall portion at the top of said stopper portion and receivable in the mouth of the bottle, and a downwardly convex diaphragm-like partition spanning the interior of said stopper portion and integral therewith at a level below the region at which said stopper portion is connected to said wall portion, said stopper portion extending axially downwardly beyond said level and bulging annularly outwardly from said top down with progressively increasing Wall thickness to a zone of maximum girth and thickness confronting said inner bead at an intermediate location just below said level, application of upward pressure to said partition deflecting the bulge of the stopper portion resiliently outwardly against the inner wall of the mouth of the bottle.

2. A bottle closure as defined in claim 1 wherein said stopper portion tapers upwardly and downwardly from said zone of maximum girth.

3. A bottle closure as defined in claim 1, further comprising angularly spaced ribs integrally formed on said stopper at the upper periphery of said partition.

4. A bottle closure as defined in claim 1 wherein said stopper is composed of an elastic hard synthetic resin selected from the group which consists of polyethylene and polypropylene.

5. A bottle closure comprising a stopper unitarily formed of an elastic hard synthetic resin selected from the group which consists of polyethylene and polypropylene and consisting essentially of an outer annular wall portion provided with an inner bead and adapted to be forced over the mouth of a bottle whereby said bead underlies a head of the bottle, a central tubular generally cylindrical stopper portion connected with said wall portion at an axial extremity of said stopper portion and receivable in the mouth of the bottle, and an axially convex diaphragm-like partition spanning the interior of said stopper portion and integral therewith at a junction axially spaced from the region at which said stopper portion is connected to said wall portion in the direction of the interior of the bottle, said stopper portion extending axially in said direction beyond said junction in said direction and bulging annularly outwardly away from said junction, said partition being convex in said direction whereby application of pressure to said partition in the opposite axial direction deflects the bulging extension of the stopper portion resiliently outwardly against the inner wall of the mouth of the bottle, said stopper being formed with an annular groove in the region at which said stopper portion is connected with said wall portion.

References Cited UNITED STATES PATENTS 2,325,309 7/1943 Swart.

2,696,318 12/1954 Kihm 2154O 3,116,846 1/1964 Salminen 21541 3,209,934 10/1965 Salminen 215-41 FOREIGN PATENTS 1,339,800 9/1963 France.

JOSEPH R. LECLAIR, Primary Examiner.

GEORGE O. RALSTON, Examiner.

R. PESHOCK, Assistant Examiner. 

1. A BOTTLE CLOSURE COMPRISING A STOPPER UNITARILY FORMED OF A SYNTHETIC RESIN AND CONSISTING ESSENTIALLY OF AN OUTER ANNULAR WALL PORTION PROVIDED WITH AN INNER BEAD AND ADAPTED TO BE FORCED OVER THE MOUTH OF A BOTTLE WHEREBY SAID BEAD UNDERLIES A BEAD OF THE BOTTLE, A CENTRAL TUBULAR GENERALLY CYLINDRICAL STOPPER PORTION HINGEDLY CONNECTED WITH SAID WALL PORTION AT THE TOP OF SAID STOPPER PORTION AND RECEIVABLE IN THE MOUTH OF THE BOTTLE, AND A DOWNWARDLY CONVEX DIAPHRAGM-LIKE PARTITION SPANNING THE INTERIOR OF SAID STOPPER PORTION AND INTEGRAL THEREWITH AT A LEVEL BELOW THE REGION AT WHICH SAID STOPPER PORTION IS CONNECTED TO SAID WALL PORTION, SAID STOPPER PORTION EXTENDING AXIALLY DOWNWARDLY BEYOND SAID LEVEL AND BULGING ANNULARLY OUTWARDLY FROM SAID TOP DOWN WITH PROGRESSIVELY INREASING WALL THICKNESS TO A ZONE OF MAXIMUM GIRTH AND THICKNESS CONFRONTING SAID INNER BEAD AT AN INTERMEDIATE LOCATION JUST BELOW SAID LEVEL, APPLICATION OF UPWARD PRESSURE TO SAID PARTITION DEFLECTING THE BULGE OF THE STOPPER PORTION RESILIENTLY OUTWARDLY AGAINST THE INNER WALL OF THE MOUTH OF THE BOTTLE. 